Browse Prior Art Database

Stacking Ring

IP.com Disclosure Number: IPCOM000045035D
Original Publication Date: 1983-Jan-01
Included in the Prior Art Database: 2005-Feb-06
Document File: 2 page(s) / 47K

Publishing Venue

IBM

Related People

Gautesen, VB: AUTHOR [+2]

Abstract

In the packaging of certain semiconductor chips, it is necessary to secure a substrate, with a chip and stacking pins thereon, to another substrate having the necessary I/O pins. One technique is to place one substrate on top of another substrate with the pins of the top substrate aligned with the pin heads on the bottom substrate. The pins on the top substrate are prepared by solder/fluxing the pins that will be placed on pin heads of the bottom substrate. This structure is then heated to cause the solder to melt and form a connection between the two substrates. In order to assure a proper connection, it is necessary to align the substrates initially, but permit slight shifting of the two upon heating to allow for differences in alignment due to manufacturing tolerances.

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Stacking Ring

In the packaging of certain semiconductor chips, it is necessary to secure a substrate, with a chip and stacking pins thereon, to another substrate having the necessary I/O pins. One technique is to place one substrate on top of another substrate with the pins of the top substrate aligned with the pin heads on the bottom substrate. The pins on the top substrate are prepared by solder/fluxing the pins that will be placed on pin heads of the bottom substrate. This structure is then heated to cause the solder to melt and form a connection between the two substrates. In order to assure a proper connection, it is necessary to align the substrates initially, but permit slight shifting of the two upon heating to allow for differences in alignment due to manufacturing tolerances. The surface tension of the melting solder will actively cause the required shift of the substrates with respect to the manufacturing tolerances during heating.

The fixture, as shown in the figure, provides the initial precise alignment of the substrates, while permitting the required shifting during heating, but still confining the shift to within allowed limits.

As shown in the figure, a top substrate 10, formed of ceramic, is provided having a chip 12 mounted thereon. Stacking pins 13 pass through the substrate
10. A bottom substrate 14, also formed of ceramic, is provided having I/O pins 18 with heads 16 formed thereon in approximate alignment with the pins 13 on the underside o...